Portable riser

ABSTRACT

A portable riser having a plurality of steps which have a travel position in superimposed relation with structure for rolling the riser along the floor, hinge means interconnecting the steps whereby they may be folded out of superimposed relation, a pair of sliders pivotally associated with each step and which are hinged to sliders of an adjacent step by said hinge means whereby lifting of one step causes erection of the riser to an erected position, and latch means automatically operable to prevent movement of the steps beyond erected position and to lock the riser in erected position for use.

BACKGROUND OF THE INVENTION

This invention relates to a portable riser usable by choral groupseither singly or in combination with other risers as well as by othergroups including bands and orchestras.

The prior art has structures for stands or risers which can be movedbetween a storage position and an erect position for use. A structure ofthis type is shown in Ellis U.S. Pat. No. 2,598,983. The stand of thispatent has no specific structure for portability and does not have anarrangement whereby the steps may be moved into a superimposed relationfor travel.

The Mackintosh U.S. Pat. No. 2,859,488 discloses a stand with stepsmovable between a storage position and an erected position and hascasters for portability. However, it is necessary to physically turn theentire unit between a position wherein the casters engage the floor anda position whereby the stand may be erected.

The Berg U.S. Pat. No. 3,229,430 discloses a choir riser wherein aplurality of steps are in superimposed relation for storage and whichmay be opened out and then the stand erected for use. There is nodisclosure of structure facilitating portability of the unit, such ascasters movable along a floor. Additionally, the structure of thispatent requires turning of the entire unit to an upside down position inorder to move the riser components between a storage position and anerected position.

The assignee of this application has U.S. Pat. Nos. 3,747,706 and3,747,708 relating to a portable riser. In the structures of thesepatents, it is necessary to turn the riser between a travel position anda position for erection. These patents also show an optionally usablefourth step and the first of these patents shows a guard rail hinged tothe unit for positioning at a level above and to the rear of theuppermost step.

SUMMARY

A primary feature of the invention disclosed herein is to have aportable riser which may be moved between travel and erected positionsby one person and without any turning of the entire structure, but withonly folding and unfolding of steps into and out of superimposedrelation and with lifting force applied to a single step to move theentire riser to an erect position and with automatically operable meansto limit movement of the riser to an erected position and to latch thestructure in erected position.

In accomplishing the foregoing, a plurality of steps are hinged togetherwhereby the uppermost step is at the bottom of the superimposed stepswhen in travel position and the uppermost step has structure associatedtherewith including casters and a handle to facilitate movement of theriser when in travel position. With the uppermost step resting on thefloor, the other steps may be folded out to a side-by-side relation withthe uppermost step, followed by lifting of the uppermost step to bring apair of sliders hinged to the underside of the uppermost step to anerect, supporting position and which by interconnecting hinge meanssimilarly brings the sliders associated with the other steps to an erectposition.

Additional features of the invention reside in the automaticallyoperable latch structure for limiting movement of the riser to an erectposition and holding the riser in said erect position, including amanually operable lock for firmly securing the latch in position andremoving any play from the structure; an optionally usable fourth stepand a guard which may be associated with either a three-step riser or afour-step riser, with each of the fourth step and the guard having asimilar type of clamp structure for securing to vertical sections of thesliders of an adjacent step and with the guard having a pair ofdepending legs which engage the floor when used with a three-step riseror engage a strut on the fourth step of a four-step riser to providevertical support for the guard.

The portable riser is constructed of parts that are bolted togetherwhereby the unit may be shipped disassembled for economy in shippingcosts and, additionally, a replacement part may be ordered by anydamaged part and easily installed.

The portability of the unit and ease of erection is accomplished bycasters associated with a slider of the uppermost step which is infloor-engaging position and which are moved out of floor-engagingposition as the riser is erected. Additionally, a handle, in the form ofa U-shaped member, is mounted to the opposite end of the uppermost stepto facilitate lifting and guiding of the riser when in travel positionand with this handle also functioning as an interlock member to engagebeneath the frame of an uppermost step of an adjacent riser in order tolock plural risers together when in erected position. This U-shapedmember is releasably fastened by clamp means to the underside of a stepand, more particularly, to a peripheral frame member of a step and asmany of these members may be mounted and used as is deemed necessary toprovide for interlocking of adjacent risers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the portable riser in travel positionand being transported;

FIG. 2 is a perspective view showing an initial operation in theerection of the riser;

FIG. 3 is a perspective view, similar to FIG. 2, showing the relation ofthe parts after completion of the operation illustrated in FIG. 2;

FIG. 4 is a perspective view, looking toward the rear of the riser inerected position;

FIG. 5 is a fragmentary, perspective view, looking toward the rear ofthe portable riser in erected position and from the opposite directionof the view of FIG. 4;

FIG. 6 is a fragmentary, vertical section, taken generally along theline 6--6 in FIG. 5;

FIG. 7 is a sectional view, with parts broken away, taken generallyalong the line 7--7 in FIG. 6;

FIG. 8 is a fragmentary, perspective view, similar to the view of FIG.4, and showing a guard attached thereto with two different clampelements in different positions;

FIG. 9 is a fragmentary elevation, taken along the line 9--9 in FIG. 8and with the step shown in section;

FIG. 10 is a sectional view, taken generally along the line 10--10 inFIG. 8;

FIG. 11 is a perspective view, looking toward the front of the portableriser with an optional fourth step and the guard rail associatedtherewith and an adjacent riser also shown but broken away;

FIG. 12 is a fragmentary, perspective view, similar to FIG. 4, of thestructure shown in FIG. 11;

FIG. 13 is a section, taken generally along the line 13--13 in FIG. 12;

FIG. 14 is a sectional view, taken along the line 14--14 in FIG. 11; and

FIG. 15 is a bottom plan view of the structure shown in FIG. 14.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The portable riser is shown generally in FIGS. 1 to 4 and has anuppermost step 20, an intermediate step 21, and a lowermost step 22.Each of these steps is of a construction shown particularly in FIG. 14wherein a peripheral frame 23 has a board 24 which may be covered withmaterial, such as carpeting, and which is locked into the frame by clips(not shown) and which results in an upwardly open channel 25 beneath theboard 24 and extending around the periphery of each step. This channelis for receiving the clips referred to above and for a purpose morefully described hereinafter.

In the travel position, the uppermost step 20 is positioned beneath andin facing relation with the intermediate step 21 and with the lowermoststep 22 on top, as shown in FIG. 1 and as indicated by the partialerection operation shown in FIG. 2. The riser is easily moved by meansof a pair of casters 30 and 31 which engage the floor when transportingthe riser and with a handle 32 being disposed at an end of the uppermoststep 20 for manual engagement as shown in FIG. 1.

With the portable riser shown in erected position in FIGS. 4 to 6, itwill be noted that each of the steps 20-22 has a pair of floor-engagingsliders associated therewith. These sliders are all of a U-shape, with acentral part for engagement with the floor and with a pair of legs whichhinge to the underside of a step. More specifically, each of the slidersis formed of bent tubular stock and is provided with suitable openingsto receive attaching bolts for association with structure to bedescribed.

The uppermost step 20 has a pair of sliders, indicated generally at 40and 41, with each slider being of the same construction and having acentral part 42 and legs 43 and 44 which extend upwardly and are hingedto the underside of the step by a pair of bolts 45 and 46 (FIG. 9)connected to a bracket 47 secured to the underside of the step board 24.

The sliders 40 and 41 extend downwardly normal to the uppermost step 20when in erected position, as shown in FIGS. 4, 8 and 9, while extendinggenerally parallel to the uppermost step when in travel position, and asshown in FIG. 1. The sliders 40 and 41 are caused to move in unisonrelative to the step 20 by a strut 48 extending between the legs 43 ofthe pair of sliders and pivotally connected thereto at its opposite endsby bolt means 49. The casters 30 and 31 are each individually carried bya frame 50 bolted to the legs 43 and 44 of the slider 41 and positionedwhereby they are located to engage the floor for travel, as shown inFIG. 1, but are out of engagement with the floor when the riser is inerected condition, as shown in FIG. 4.

The intermediate step 21 has a pair of sliders, indicated generally at51 and 52, of the same construction as the sliders 40 and 41, but havinga lesser height whereby the step 21 is at a level beneath the uppermoststep 20 when the riser is erected and as shown in FIG. 4. Each of thesliders 51 and 52 has a pair of legs 53 and 54, with the legs 53 beingconnected to the legs 44 of the sliders 40 and 41 by first hinge means55 and 56. These hinge means have hinge leaves of a width sufficient tospan a riser step and the hinge leaves are secured to vertical sectionsof the slider legs whereby the riser steps 20 and 21 may be insuperimposed facing relation when in travel position.

The lowermost step 22 has a pair of sliders, indicated generally at 57and 58, which are of the same construction as the other sliders, butwhich have vertical legs 59 and 60 of an even shorter height than thelegs 53 and 54 of the slider 51 to have the step 22 at a level lowerthan the intermediate step 21. The legs 59 of the sliders 57 and 58 arehinged to the legs 54 of the sliders 51 and 52 by second hinge means 61and 62 which provide for positioning of the lowermost step 22 insuperimposed back-to-back relation with the intermediate step 21 when intravel position.

Assuming the portable riser is to be placed into use, it is moved to adesired location by transport in the manner illustrated in FIG. 1 andthen the handle end is lowered to the floor. One person may then movethe steps out of superimposed relation to the position shown in FIG. 3,with an intermediate position being illustrated in FIG. 2. The personthen moves to a location adjacent the slider 41 and may place a foot onthe exposed central part 42 thereof to hold the central part in oneposition on the floor and then lifts and pulls the uppermost step 20which erects the riser by movement in the direction indicated by thearrow 70 in FIG. 4. There is simultaneous movement of the slider 40 withthe slider 41 through the connecting strut 48, with the sliders 51, 52,57 and 58 of the steps 21 and 22 being caused to move simultaneously bythe hinge means 55, 56, 61 and 62 interconnecting the sliders.

Automatically operable latch means, shown particularly in FIGS. 5, 6 and7, function to limit the erecting movement of the riser to the positionshown in FIGS. 4 and 5 and to latch the structure in this position. Thisstructure includes a frame 80 pivotally mounted at its upper end by apivot pin 81 to a bracket 47 secured to the underside of a step board24. The frame 80 has a planar bottom panel 81 and sides which are shapedto form a pair of channels 82 and 83 for slidably receiving a pair ofrods 84 and 85, each of which are pivotally mounted at their lower endto a pin 86 carried on a bracket 87 secured to a central part 42 of theslider 41. The nonpivoted ends of the rods 84 and 85 are interconnectedby a spring member 88 which urges the rods apart from each other andtoward the lateral walls of the channels 82 and 83 of the frame 80. Amanually operable lock 90 coacts with the latch structure and is shownin an unlocked position in FIG. 5 and in locked position in FIGS. 6 and7. When the lock 90 is in unlocked condition, the pivotally mounted endsof the rods 84 and 85 are permitted to move lengthwise along the pin 86,but are prevented from such movement when the lock 90 is in lockedposition.

The frame 80 has a pair of detent notches 91 and 92 which coact withdetent pins 93 and 94, respectively, on the rods 84 and 85. With theriser in a travel position, the rods 84 and 85 are extended into theframe 80 a much lesser distance than shown in FIGS. 5, 6 and 7 and thedetent pins 93 and 94 are outside the frame 80 and remote from thedetent notches 91 and 92. As the uppermost step 20 is raised, the rods84 and 85 move lengthwise of the frame 80 and initially the detent pins93 and 94 contact cam surfaces 95 and 96 on recessed flanges of theframe channels whereby the rods are moved toward each other against theaction of the spring interconnector 88 and then the rods move furtherlengthwise of the frame 80 until the detent pins 93 and 94 contact thewalls of the detent notches 91 and 92 and which lie in the path of thedetent pins. This limits the relative lengthwise movement of the latchmechanism and determines the erected position of the riser. The springinterconnector 88 forces the detent pins 93 and 94 outwardly into thedetent notches 91 and 92 wherein the riser is automatically latched inerected position. This action has required the pivoted ends of the rods84 and 85 to move toward and away from each other, as is permitted bytheir movement along the pin 86. In order to lock the latch mechanism,the manually operated lock 90 is moved from the position of FIG. 5 tothe position shown in FIGS. 6 and 7. The lock 90 includes a cover plate98 and a pair of wedge plates 99 and 100 on the underside thereof, allof which have the pin 86 loosely received therein for pivoting thereonand with the wedge plates 99 and 100 being at an angle to force thelatch rods 84 and 85 to their outermost position relative to the pin 86and against the depending walls 101 and 102 of the cover plate (FIG. 7)whereby all play is taken out of the latch structure and the latch islocked.

In order to return the portable riser from erected condition to travelposition, an operator releases the manually-operated lock 90 and movesit to the position shown in FIG. 5. The rods 84 and 85 are moved towardeach other to release the detent pins 93 and 94 from their respectivedetent notches and then the uppermost step 20 is gradually lowered tothe position shown in FIG. 3 with resulting simultaneous loweringmovement of the other steps. The steps are then folded from the positionof FIG. 3 to the position of FIG. 1 and the portable riser may then betransported to another location or to storage, with the entire operationbeing accomplished by one person.

An optionally usable guard 110 is shown in association with the riser inFIGS. 8 to 10. This guard has a guard rail 111 located at a distanceabove the uppermost step and a pair of legs 115 and 116 dependingdownwardly from the guard rail into engagement with the floor. Each ofthese legs extends adjacent to a leg 43 of the sliders 40 and 41. Eachof the guard legs carries attachment means including an elongatevertically extending three-sided bracket 117 which is secured theretoand has an open side to move laterally onto a leg 43 of a slider and asshown in FIG. 10. The attachment means of each guard leg also includes aU-shaped cross-section clip 118 which is pivoted to the guard rail legby a pivot pin 119 and which is movable from the released position,shown for the clip associated with guard rail leg 116, to the lockedposition shown for the clip associated with the guard rail leg 115. Thebracket 117 associated with the slider leg 43 locks the guard rail legfrom rearward movement relative to the riser while the clip 118, whenmoved downwardly into locked relation, holds the parts in assembledrelation and against relative lateral movement.

FIGS. 11 and 12 show the portable riser with an optionally usable fourthstep and with the guard 110. The fourth step 150 has a pair of sliders,indicated generally at 151 and 152, associated therewith which are ofthe same construction as the other sliders previously described, butwith the legs 153 and 154 of each slider having a greater height toplace the fourth step 150 at a higher level. Each of the sliders ispivotally connected to the underside of the step 150 by pivot bolts 155secured to brackets 47 on the underside of the step board and thesliders are interconnected by a strut 156 which, at its opposite ends,is pivotally connected by bolts 157 and 158 to the slider legs 153. Eachof the slider legs 154 carries a J-shaped bar secured to the lower endthereof and with a part 160 extending forwardly therefrom. Each of theslider legs also carries attachment structure, similar to thatpreviously described for attaching the guard to the riser. Thisattachment structure includes an elongate three-sided bracket 161secured to the leg and open on one side to laterally fit upon the sliderleg 43 of the uppermost step 20 and a U-shaped cross-section clip 162which can be pivotally moved from an out-of-the-way position to thelocked position shown in FIG. 13 where it spans the slider leg 154, theslider leg 43 and the bracket 161. The clips 162 are pivoted to theslider legs 154 by pivot pins 163. For proper spacing of adjacent legsof sliders 40 and 151 and 41 and 152, there are spacer plates 164secured within the elongate bracket 161 with the positioning thereofshown particularly in FIG. 13.

After the three-step riser is erected, the fourth step unit is moved toa position adjacent thereto and with the sliders 151 and 152 extendingat a slight angle from the normal to the step 150. The bar legs 160 areplaced in engagement with the central base parts of the sliders 40 and41 and the sliders 151 and 152 are then moved fully erect and at thesame time elongate brackets 161 are moved laterally onto the legs 43 ofthe sliders 40 and 41. Following this, the U-shaped clips 162 are moveddownwardly about their pivot pins 163 to lock the fourth step to thethree-step unit.

The guard 110 shown in FIGS. 11 and 12 is the same guard as shown anddescribed in FIGS. 8 to 10. When mounted to the fourth step unit, thelower ends of the guard legs 115 and 116 do not rest upon the floor, butrest upon the upper sides of the strut 156 to hold the guard in theproper elevated position. The attachment structure, including theU-shaped clips 118 for the guard are assembled to the slider legs 153 ofthe fourth step in the same manner as they are assembled to the sliderlegs 43 of the uppermost step 20, as previously described.

As shown in FIG. 11, a similar portable riser may be associated withthat described herein and with the similar portable riser havingcomparable steps 20a, 21a, 22a and 150a. The adjacent steps may beinterlocked where desired by use of a handle 32 which, as shown in FIG.1, is used to facilitate manual handling of the riser when in travelposition. The interlocking function of such a handle is shown in FIGS.14 and 15. The handle is in the form of a U-shaped member with anintermediate part 180 and a pair of legs, one of which is shown at 181.The pair of legs extends beneath an end of a step and the intermediatepart 180 lies in spaced parallel relation with the end of the step andbeneath the level thereof to engage beneath the peripheral frame of astep of an adjacent riser. As shown in FIGS. 14 and 15, the handle 32 onstep 22a has an intermediate part 180 beneath the step board 24 of thestep 22 and under the open channel 25 of the peripheral frame thereof tolock the riser steps 22 and 22a. This interlocking is accomplishedmerely by tipping of one unit relative to the other to bring about theinterfitting relation shown in FIG. 14. The handles which are also usedfor interlocking may be positioned wherever desired by means ofreleasable clamp structure which includes a bracket 182 welded to theleg 181 with a flange 183 underlying the channel 25 and a pair ofsurfaces 184 and 185 abutting against the edge of the channel. A bolt186 passes through an opening in this bracket and is threadably receivedwithin a clip 187 which engages between the underside of the step board24 and the interior of the channel 25 whereby tightening of the boltdraws the clip and bracket together in tight relation with forcereactions against the step board and the channel. Similar releasableclamp structure is associated with the other leg of the U-shaped member32. With this structure, it is possible to attach a handle functioningas an interlock for adjacent riser steps at the ends of one or moresteps of a riser. It will be understood that only one handle 32functions for transport of the riser as shown in FIG. 1.

We claim:
 1. A portable riser having a plurality of steps of increasingelevation rearwardly of the riser, a pair of floor-engaging slidershinged to the underside of each step for pivotal movement about parallelaxes transverse to the length of a step whereby said steps may be movedfrom a travel position adjacent and parallel to said sliders to anerected position normal to said sliders, hinge means interconnectingsliders of adjacent steps for pivotal movement about axes lengthwise ofthe height of said sliders whereby said steps may fold relative to eachother when said sliders are in said travel position, said hinge meansincluding first hinges interconnecting the uppermost step and anintermediate step for movement between a superimposed facing relationwhen in a travel position and a side-by-side position and second hingemeans connecting said intermediate step and lowermost step for movementbetween a superimposed back-to-back relation in a travel position and aside-by-side position, and automatically engageable latch meansinterconnecting a step and one of said associated pair of sliders tohold said riser in erected position.
 2. A portable riser as defined inclaim 1 wherein said latch means includes a manually operable lock tohold said latch means in engagement.
 3. A portable riser as defined inclaim 2 wherein said latch means includes a frame pivoted at an end to astep, a pair of rods pivoted at an end thereof to a slider and movablelengthwise of said frame, and interengaging detent means on said rodsand frame for holding said rods and frame in a predetermined positionlengthwise of each other.
 4. A portable riser as defined in claim 3wherein said frame has a pair of guide channels, spring means connectedto said rods urging the rods apart and into said guide channels, andsaid detent means including a pin on each of said rods and a notch in achannel with the pin being urged into said notch by said spring means.5. A portable riser as defined in claim 4 wherein said manually operablelock includes a pivotally mounted plate and cam members thereon movablebetween said pair of rods to force said rods apart and maintain saidpins in said notches.
 6. A portable riser as defined in claim 1including casters on one slider of the uppermost step and a handle atthe opposite end of the last-mentioned step whereby said riser may bemoved on said casters when in a travel position, and said casters beingpositioned to move off the floor as the riser is erected and supportedby said sliders.
 7. A portable riser as defined in claim 6 wherein saidhandle extends outwardly from said end of the uppermost step, and anuppermost step having a peripheral frame open at the underside to fitover said handle and interlock two adjacent risers in end-to-endrelation.
 8. A portable riser as defined in claim 7 wherein said handleis generally U-shaped and with the legs thereof extending under a step,and releasable clamp means for attaching the handle to an end of anystep.
 9. A portable riser as defined in claim 1 including an optionallyusable additional step positionable to the rear of said uppermost step,a pair of floor-engaging sliders pivotally connected to said additionalstep, means on the last-mentioned sliders for engaging and locking tothe sliders of said uppermost step.
 10. A portable riser as defined inclaim 9 wherein said engaging and locking means includes an elongatebracket open along one side to receive an elongate portion of a slider,a bar to engage an adjacent slider base, and a swingable U-shaped clipmovable to a position spanning adjacent elongate portions of two slidersfor locking said sliders together.
 11. A portable riser as defined inclaim 9 including a guard positionable above said additional step andhaving a pair of depending legs, a strut pivotally connected between thesliders of said additional step and positioned to be engaged by thelower ends of said legs for vertical support thereof, and means forattaching said legs to the sliders of the additional step including anelongate bracket having an opening to receive a section of a slider, anda swingable U-shaped clip movable to a position spanning a leg and saidslider section.
 12. A portable riser as defined in claim 1 whereinadditional structure is attached to the rear of said riser by connectionto vertical sections of the sliders of the uppermost step and attachmentmeans carried by said additional structure including an upright brackethaving an open side to fit on one of said slider vertical sections toprevent movement of said additional structure rearwardly of said riser,and a U-shaped clip movable to a position spanning a part of saidadditional structure and said slider vertical section to preventmovement from side to side of the riser.
 13. A portable riser as definedin claim 1 wherein a guard is attachable to said uppermost step and hasa pair of floor-engaging legs, and attachment means carried by each legincluding an elongate bracket with an open side to receive a verticalsection of a slider and lock the guard against rearward movement, and aU-shaped clip pivotally mounted on a leg for movement to a positionspanning said leg and slider vertical section to lock the leg againstmovement sideways of the riser.
 14. A portable riser as defined in claim1 wherein each of said sliders is formed of tubular stock and generallyof a U-shape to have a base for floor engagement and a pair of legs,said hinging being to the upper ends of said legs, a strut pivotallyconnected to both of the sliders of the uppermost step for causinguniform movement of all the sliders between travel and erectedpositions, and said first and second hinge means being bolted to thelegs of said sliders.
 15. A portable riser as defined in claim 1 whereineach of said steps has a peripheral frame with an open channel on theunderside, a U-shaped member with an intermediate part and a pair oflegs, said pair of legs extending beneath an end of a step and saidintermediate part lying in spaced parallel relation with said step endand beneath the level thereof to engage beneath the peripheral frame ofan adjacent step end of another riser, and releasable clamp meansengaging said legs and positioned within said open channel to lock saidU-shaped member with a selected step.
 16. A portable riser as defined inclaim 1 and including a guard positionable at a level above theuppermost step, said guard including a pair of support legs, and lockingmeans for attachment to a pair of sliders including a pair of elongatethree-sided brackets attached one to each leg for lateral fitting onto avertical section of each of said sliders to prevent rearward movement ofsaid legs, and a pair of U-shaped clips pivotally mounted one on eachleg movable to a position to span a leg, a slider vertical section and abracket to lock said last-mentioned parts together.
 17. A portable riseras defined in claim 1 wherein a strut pivotally interconnects thesliders of at least one step to assure simultaneous movement of saidsliders in movement of the riser between travel and erected positions,and said latch means includes interengaging sliding parts with a springloaded detent on one part movable into a notch in the other part whensaid riser has been moved to an erected position whereby the erectedposition is automatically obtained.
 18. A portable riser having aplurality of steps of increasing elevation rearwardly of the riser, apair of floor-engaging sliders for each step and each slider being of aU-shape with an intermediate part resting on the floor and a pair ofupstanding legs pivotally connected at their upper ends to the undersideof a step, a first pair of hinges interconnecting the sliders of anuppermost step and an intermediate step with hinge leaves of a widthequal to the thickness of a step and positioned to permit thelast-mentioned steps to be in superimposed facing relation when in atravel position, a second pair of hinges interconnecting saidintermediate step and a lower step with hinge leaves of a lesser widththan said first pair of hinges and positioned to permit thelast-mentioned steps to be in a superimposed back-to-back relation in atravel position, caster means on one of the sliders of the uppermoststep whereby the superimposed steps may be transported, and erection ofthe riser is obtained by unfolding said steps out of superimposedrelation while the casters are on the floor followed by lifting of thesteps relative to the sliders to place the sliders in support positionbeneath the steps, and automatically operable means interconnecting astep and an associated slider to limit lifting movement of the steps andhold the riser in erected position. .Iadd.
 19. A portable riser movablebetween erected and travel positions without turnover and having aplurality of steps of increasing elevation rearwardly of the riser, apair of floor-engaging sliders hinged to the underside of each step forpivotal movement about parallel axes transverse to the length of a stepwhereby said steps may be moved from a travel position adjacent andparallel to said sliders to an erected position normal to said sliders,hinge means interconnecting sliders of adjacent steps for pivotalmovement about axes lengthwise of the height of said sliders wherebysaid steps may fold relative to each other when said sliders are in saidtravel position, said uppermost step having its pair of sliders restingon the floor in both travel and erected positions, said hinge meansincluding first hinges interconnecting the sliders of the uppermost stepand of the intermediate step and having all the hinge leaves with anexposed width at least equal to the thickness of a step whereby theuppermost and intermediate steps are movable between a superimposedfacing relation when in a travel position and a side-by-side position,the sliders of the last-mentioned steps having the thickness of twosteps therebetween when in said travel position, second hinge meansconnecting said intermediate step and lowermost step for movementbetween a superimposed back-to-back relation in a travel position and aside-by-side position, and automatically engageable latch meansinterconnecting a step and one of said associated pair of sliders tohold said riser in erected position and moved to latch position as theriser is erected. .Iaddend. .Iadd.
 20. A portable riser as defined inclaim 19 wherein said latch means includes a frame pivoted at an end toa step, a pair of rods pivoted at an end thereof to a slider and movablelengthwise of said frame, and interengaging detent means on said rodsand frame for holding said rods and frame in a predetermined positionlengthwise of each other. .Iaddend. .Iadd.21. A portable riser asdefined in claim 20 wherein said frame has a pair of guide channels,spring means connected to said rods urging the rods apart and into saidguide channels, and said detent means including a pin on each of saidrods and a notch in a channel with the pin being urged into said notchby said spring means. .Iaddend.